When Hunga Tonga-Hunga Ha‘apai erupted in Tonga on January 15, sending a shockwave around the globe, it rewrote scientists’ understanding of volcanology and tsunamis.
 
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April 12, 2022
 
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The island that blew up

It's a quiet place for an active volcano.

Waves crash into dark rocks. There are no steaming fumaroles, bubbling pools or rumbling from deep within the earth. Just a few months ago, though, the ground where Shane Cronin and Marco Brenna now stand didn’t exist.

It’s November 2015. About a year earlier, smoke and ash plumes began to emanate from the sea here: signs of an underwater volcano in action. The submarine eruption continued into the new year, escalating on January 11, 2015, with smoky plumes jetting nine kilometres into the sky, and wet ash and rock chunks spewing into the air and sea. Five days later, a new landform had emerged: a volcanic cone, a little shorter than Auckland’s Maungarei/Mount Wellington, artfully enclosing a jewel-like crater. Keep reading...

 
 
 
 
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What happened on Whakaari?

The eruption started at 9.35pm, with big heaves inside the crater. At 10.03pm, it began pelting the walking track with projectiles, but withheld its final energy until 10.11pm when, with a whoomph, it sent the plume sky-high. A scalding current of steam and debris, coloured green by the hydrothermally altered rock it contained, rolled right over the walking track at 11 metres per second, and down to the south-eastern bays. This eruption took place on Whakaari/White Island on April 27, 2016. Keep reading...

 
 
 
 
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Secret passages

Lava caves may just be the most delightful thing that Aucklanders don’t know about their city—hidden below the suburbs, beneath front lawns and corner dairies.

They are formed as a stream of lava begins to cool. The surface of it solidifies, but molten rock continues to flow beneath, kept fluid by the insulating crust. More often than not, the tunnel fills up and sets solid, but every now and again, if the flow isn’t blocked, a cave is created. Keep reading...